Reception falling out and birthday party

[Babybrain26]

Our son is friends with another kid in his class (he's a bit older) and seems to be quite controlling of him. In October his friend starting telling him that he couldn't play with them (and small group of 3 friends) thankfully the other kid stood up for him and played with him. This went on for a few week or so I believe until he told me what was happening, I then mentioned it to the teacher (not naming the child involved) the teacher and assistant caught them out though in the playground and told him not to act like that.

It happened again in class a few days later when he took items from his desk and started shouting at our son in class, the teacher told him to apologise and put him out of the class. All of this had died down for a good few months until we saw the child at the weekend in a club close to us and he was there with his grandma (whom I didn't know) my son spotted him instantly, seemed OK, the other kid was smiling at him but he was settled at another table with other people who I assumed he knew so I didn't interrupt. I asked my son if he wanted to sit beside him and he said no, I said ok then (he was tired tbh and is very shy generally). I had to pop out to take him and his sibling to the bathroom. We settled in another part of the room and the kid passed us so I said hello and he blanked me (not that i was worried, just thought it strange.) The grandma just sat on the sideines anyway, come Monday the kid started isolating our son again, pointing out differences with his peers. On the Tuesday he shouted at him not to line up with the others and to go away. Our son ended up crying at this. The teacher walked with him to find out what was wrong, he lied and said he was just missing his parents. At pickup they told us he had been crying but they didn't really know why. At home he told me why so I informed the teacher. She said she would speak to the other kid the next day. She then updated me the following day to say she had phoned the parents to encourage him to use kind words with his peers (I'm not sure if my son's name was mentioned or not specifically). We have a class birthday party to attend next week and his parents will be there. I'm not sure if we should still go, or if we do how I should handle this. (I'm not one for confrontation). It seems awkward now.

OP I have a child a similar age and have inadvertently ended up in a similar drama triangle. I've learned just to talk to my child about kindness and what's important in friendships from time to time and otherwise just leave them to it. They have to figure it out for themselves. Don't take it personally. You will never know 100% what's gone on at school so there's no point in interfering too much. If they want to be friends then they will be.

So the same kid hit my kid 3 times in the past two weeks. I asked the teacher (a new p/t one) to keep an eye on things, they seemed to be unaware of the previous instances. My son said two of his classmates stepped in and told the other p/t teacher. The teacher I messaged called them both in and told off the child again. Another party last week but we didn't attend due to illness, the mum seems to be keeping an eye on the parents I'm friendly with and following up on her version of my son and me which is making others avoid us/ tell their kids to stay away from my kid (including a neighbour a few doors down). I had said to one of the parents if they wanted a play date sometime to let us know. They told the mum of the kid who keeps hitting my son (probably not realising) and she's created a fuss as I didn't invite her child. And the other parent thinks I'm mean for excluding him. I only asked one kid, it wasn't a party or anything. Should I just let this play out? She's painting us as the villains in her story though and making others question us. I've advised my child to stay away from this kid but he can't he says...he acts out at home with his sibling when hes with this kid.